1. Field of the Invention
The invention relates to a sun-shade assembly for a automobile, more particularly to a motorized sun-shade assembly.
2. Description of the Related Art
A sun-shade assembly is generally installed in an automobile adjacent to a rear window for shading the interior of the automobile from sun-light.
U.S. Pat. No. 5,791,721 discloses a motorized sun-shade assembly that includes a base unit, a screen unit, a pair of pivot arms, and a drive unit. The screen unit includes a lower horizontal rod mounted rotatably on the base unit, an upper horizontal shaft, and a screen with a bottom edge connected to the horizontal rod and a top edge connected to the horizontal shaft. Each of the pivot arms has a lower end portion mounted pivotally on the base unit, and an upper end portion slidably engaging the horizontal shaft. The drive unit is mounted on the base unit and includes a motor with a rotatable drive shaft which is coupled to one end of the horizontal rod. The motor is operable in a first mode, wherein the pivot arms pivot away from each other to move the horizontal shaft upwardly and stretch the screen, and in a second mode, wherein the pivot arms pivot toward each other to move the horizontal shaft downwardly and permit winding of the screen on the horizontal rod. The drive unit further includes a control unit connected electrically to the motor. The control unit is operable so as to control operation of the motor in the first and second modes, and includes a solar collector plate for collecting solar energy, a converter circuit connected to the solar collector plate for converting the solar energy collected by the solar collector plate into electrical energy, and a switch control circuit which interconnects the converter circuit and the motor. The switch control circuit includes a timer switch for deactivating automatically the motor after a preset time during operation of the motor in the first mode, and a contact switch disposed on the base unit and actuated by one of the pivot arms for deactivating the motor when the screen is wound fully on the horizontal rod.
It is noted that the timer switch does not ensure that a desired length of the screen has been stretched out of the housing when the motor is deactivated after operating in the first mode. Moreover, the timer switch can not be easily configured by the user to suit a particular window dimension of a specific type of automobile.